NAME

Net::DNS::TestNS - Perl extension for simulating simple Nameservers

SYNOPSIS

use Net::DNS::TestNS;

ABSTRACT

Class for setting up "simple DNS" servers.

DESCRIPTION

Class to setup a number of nameservers that respond to specific DNS queries (QNAME,QTYPE) by prespecified answers. This class is to be used in test suites where you want to have servers to show predefined behavior.

If the server will do a lookup based on QNAME,QTYPE and return the specified data. If there is no QNAME, QTYPE match the server will return a SERVFAIL.

A log will be written to STDERR it contains time, IP/PORT, QNAME, QTYPE, RCODE

Configuration file

The class uses an XML file to read its configuration. The DTD is documented in Net::DNS::TestNS::DTD.

The setup is split in a number of servers, each with a unique IP/port number, each server has 1 or more QNAMEs it will respond to. Each QNAME can have QTYPEs specified.

For each QNAME,QTYPE an answer needs to be specified, response code and header bits can be tweaked through the qtype attributes.

The content of the packet can be specified through ans, aut and add elements, each specifying one RR record to end up in the answer, authority or additional section.

The optional 'delay' attribute in the QTYPE element specifies how many seconds the server should wait until an answer is returned.

If the query does not match against data specified in the configuration a SERVFAIL is returned.

new

    my $server=Net::DNS::TestNS->new($configfile, {
     Verbose => 1,
        Validate => 1,
    });

Read the configuration files and bind to ports. One can use  anywhere inside the configuration file to include other XML configuration fragments.

The second optional argument is hash that contains customization parameters. Verbose boolean Makes the code more verbose. Validate boolean Turns on XML validation based on the DTD The parser is flexible with respect to the ordering of some of the XML elements. The DTD is not. Validation is on by default.

new returns the object reference on success and 0 on failure. On failure the class variable $Net::DNS::TestNS::errorcondition is set.

verbose

    $self->verbose(1);

Sets verbosity at run time.

run

Spawns off the servers and process the data.

medea

Cleanup function that kills all the children spawned by the instance. Also known by its alias 'stop'.

Configuration file example

<?xml version="1.0" standalone="no"?> <testns version="1.0"> <server ip="127.0.0.1" port="5354"> <qname name="bla.foo"> <qtype type="TXT" delay="1"> <header> <rcode value="NOERROR"/> <aa value="1"/> <ra value="0"/> <ad value="0"/> <qr value="0"/> <tc value="1"/> <id value="1234"/> <ancount value="1"/> <nscount value="1"/> </header> <ans> bla.foo. 3600 IN TXT "TEXT" </ans> <ans> bla.foo. 3600 IN TXT "Other text" </ans> </qtype> </qname> <qname name="raw.foo"> <qtype type="TXT" delay="1"> <header> <rcode value="NOERROR"/> <aa value="1"/> <ra value="0"/> <ad value="0"/> <qr value="0"/> <tc value="1"/> <id value="1234"/> <ancount value="1"/> </header> <raw>  07 74726967676572  03 666f6f  00   00 01   00 01

   <!-- Answer section -->

     c0 0c               <!-- Points up -->
     00 01               <!-- type A -->
     00 01               <!-- class IN -->
     00 00 00 05         <!-- ttl 5 seconds  -->
     00 04               <!-- RD length 4 octets -->
     0a 00 00 01         <!-- 10.0.0.1 -->
     </raw>
   </qtype>
  </qname>
    
 </server>
</testns>

Known Deficiencies and TODO

The module is based on Net::DNS::Nameserver. There is no way to distinguish if the query came over TCP or UDP; besides UDP truncation is not available in Net::DNS::Nameserver.

Earlier versions of this script used a different DTD that had no version number. The script only validates against version 1.0 of the DTD but parses the old files.

==head1 ALSO SEE Net::DNS::TestNS::DTD, Net::DNS, Net::DNS::RR

AUTHOR

Olaf Kolkman, <olaf@net-dns.org<gt>

COPYRIGHT AND LICENSE

Permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation, and that the name of the author not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission.

THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS; IN NO EVENT SHALL AUTHOR BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.